The present invention relates to dark-blue bisazo compounds or salts thereof usable in dyeing or printing on fiber materials, particularly cellulose fiber materials, and their applications on fiber materials.
As reactive dyes of dark-blue color usable in dyeing or printing on cellulose fiber materials, dyes disclosed in JP-A-57-78458, JP-A-57-198757 and the like have been known.
The present inventors have conducted extensive researches for developing bisazocompounds or salts thereof capable of giving dyed products of dark-blue color which are superior in dyeing power, dyeing reproducibility, leveling property and dyeing performances such as build-up property, effective dyeing rate and washing-off property compared with the known dark-blue dyes described above, and which are excellent in various fastness such as chlorine fastness, light fastness, perspiration fastness, perspiration-sunlight fastness, acid-hydrolysis fastness, alkali fastness, washing fastness and peroxide washing fastness. As the result, they have found that the aim can be attained with specific diazo compounds or salts thereof having two triazine rings and the one triazine ring being substituted with one vinylsulfone fiber-reactive group through a divalent connecting group. The present invention thus have been completed.